hawk533 said:
It's been a while since I played it, but I thought that Starcraft did a pretty good job of using all three corners of the conflict triangle. I remember several missions where all you're supposed to do is not die long enough for help to come. I also remember sneaking into facilities to rescue allies.
So it is possible for a game to use all three corners and it makes for a sweet game, as anyone who has played Starcraft will agree.
This is true even in multiplayer. Enemy comes barrelling across the map? Evade, evade, evade, don't let him know you have the perfect counter-unit to his assault until he's right on the door of your base, and then mercilessly slaughter him. Wait, he's trying to get away; do you pursue or back down? Suddenly you've switched from evasion, to direct combat, and now you can choose to back off or push the assault. All it takes is a Reaver or Seige tank dropped behind the enemy base with a spotter, and now you're performing a stealth assault. The triangle shifts back and forth without ever breaking or switching genre.
Yahtzee, I think you're wrong about the bottom-right corner. When there is no direct hostility between player and enemy, you have a state of arms race. Arms race is used by many strategy and 4X games, such as Civilization and DEFCON, as well as occurring in MMOs (eg. two EVE corporations have an uneasy alliance). Now I know those aren't your favourite genres, but to disregard them is madness. Arms race is relaxing compared to the other three states, but it occurs constantly. To continue the Starcraft example above, Arms race is you and your opponent furiously researching, scouting and harvesting. When you send a harvester unit out into the field, you don't intend it to be attacked nor be attacked; at best your opponent will attempt to block it if he sees it, or mislead it across the map. A mix of arms-race and evasion/stealth.
Now, in a conventional action game, there's no "arms race" phase, as usually the enemy starts fully equipped and you have nothing to do but tech up. I guess the only equivalent is "side missions", like the races in Just Cause 2 and the glide/run events in Prototype. You're not attacking, evading, or stealthing, you're just kinda dicking around and it's really fun. Enemy can't even attack you in Prototype when you're gliding. There's conflict between you and the game (trying to get platinums is frustrating), but there's a player and an enemy and neither are attacking, you're just completing a static challenge. No direct conflict, not even indirect conflict.
I'm looking for a way to extrapolate this to other games which use this, but you're right in that the majority fail to exploit the full variety of gameplay available. The best examples I can think of for non-conflict that's still valid and fun gameplay are always presented as side-challenges. Balancing on precarious beams to get Skulls in Halo. Using the hovercraft to meet the All-Knowing Vortigaunt in HL2. It's very rarely that conflict-free arms-race/upgrade seeking is presented to you as a primary gameplay mode, just an optional (albeit sometimes necessary) section thereof. The majority of games have you upgrading and improving through direct conflict anyway - every JRPG and MMO knows it, it's called grinding.
TL;DR: Starcraft uses the full conflict triangle as described by Yahtzee. I believe there's a missing element of the conflict grid, which consists of the arms-race state, which is also underused.